126721920 has 128 divisors (see below), whose sum is σ = 435083040. Its totient is φ = 31186944.

The previous prime is 126721891. The next prime is 126721937. The reversal of 126721920 is 29127621.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22422 + ... + 27498.

Almost surely, 2^126721920 is an apocalyptic number.

126721920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 126721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (217541520).

126721920 is an abundant number, since it is smaller than the sum of its proper divisors (308361120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

126721920 is a wasteful number, since it uses less digits than its factorization.

126721920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5112 (or 5100 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 126721920 is about 11257.0831035397. The cubic root of 126721920 is about 502.2854310270.

The spelling of 126721920 in words is "one hundred twenty-six million, seven hundred twenty-one thousand, nine hundred twenty".